1. Field of the Invention
The present invention relates to an image forming apparatus and a vehicle on which the image forming apparatus is mounted; for example, an image forming apparatus including an optical scanning device for forming a two-dimensional image by scanning a light beam from an optical element, and a vehicle on which such image forming apparatus is mounted.
2. Description of the Related Art
In recent years, there has been widely proposed an optical scanning device that forms a two-dimensional image by irradiating multicolor light beams to a mirror that can scan in two-dimensional directions. Particularly, with an optical scanning device using a semiconductor laser as a light source, high light-use efficiency can be attained owing to the high directivity of a light beam irradiated from the semiconductor laser. Further, with the optical scanning device using a semiconductor laser, strong light can be generated inside the optical scanning device without requiring a large heat radiator such as a xenon lamp. In addition, owing to the high directivity of the optical scanning device using a semiconductor laser, a bright image can be formed even with a small size optical system.
An image forming apparatus such as a head-up display can be manufactured by using the optical scanning device using a semiconductor laser. Because such image forming apparatus is installed in, for example, a vehicle such as an automobile, the image forming apparatus is to be formed in a small size.
However, by pursing size-reduction of the image forming apparatus, there are problems such as being unable to attain brightness or being unable to provide a large size screen.    Patent Document 1: Japanese Laid-Open Patent Publication No. 2010-145745    Patent Document 2: Japanese Laid-Open Patent Publication No. 2010-145746